The late 80s/early 90s BBS scene was an amazing time for me. I was in high school and I've never been as interested in computers and communications as I was then. I never ventured into the "dark" side like OP--I was too scared of my parents--so I ran a legit FidoNET BBS using the RemoteAccess BBS software and the Frontdoor mailer (and later, Maximus and BinkleyTerm).
The most amazing thing about it all was that it was the public internet before there was a public internet. E-mails sent over FidoNET had an amazing weight to them that's hard to describe. It took a ton of effort just to get your BBS to participate in the network and once you did, data moved so slowly that you became very observant of each step of the process of communicating. First, you wrote the email in your mail editor (I loved GoldED). Then, another program bundled it up with other emails into some kind of binary packaging and passed it along to the mailer. The mailer took this bundle of mail and dialed out on the modem to the local FidoNET hub. If you lived in a rural location, this meant that you had to make a long-distance call to deliver the mail. My local hub was in Seguin, TX (~30 miles away) and it felt like a very big deal when my computer dialed him up to do a delivery. From there, the hub delivered it to a "star", which was a regional hub that dealt in larger volumes of mail. This was usually run by someone with money because their modems were making long-distance calls (including overseas) on a regular basis. From the star, your mail was shipped across long distances and then the process repeated in reverse until the recipient's system picked up the mail from their local hub. Then, when they replied, the whole thing happened again in reverse. It regularly took days to get a reply from across the world but it was so fun! Every single mail that you received in your inbox felt as important as someone writing a letter by hand and sending it via the postal service. I cherished getting emails, even if they were stupid.
I still dream about reviving a modern FidoNET (yes, I know it still exists) for the HN crowd. I write a lot of Go and I even read some of the FidoNET technical standards with the thought of a Go implementation of the protocols but never got anywhere in it. It's an enormous amount of work and I haven't had a real phone line in over a decade. Doing Fido over TCP/IP just doesn't feel the same. It's way too easy.